1. Field of the Invention
The present invention generally relates to roof anchor and hanging scaffold systems, and more particularly, to a system that produces a working platform hanging off the eave of a sloping roof system that is reusable, easy to deploy, and which can be quickly taken down.
2. Description of the Related Art
Worker safety is of great concern not only to construction industry employers and employees, but to federal and state governments as well, and is the subject of extensive regulation. The Occupational Safety and Health Administration (OSHA) is tasked with drafting, inspecting, and enforcing work place safety and health regulations. Notably, OSHA's construction standards number some 400 densely written pages. Brad German and Rick Schwolsky, "Better Safe Than Sorry", Builder, Vol. 18, No. 1, page 344 et seq., January 1995. See generally 29 C.F.R. 1910, which is the complete set of OSHA standards.
The need for the number and scope of such regulations is clear--construction workers face numerous and serious dangers at the job-site. OSHA's "Big Four" safety concerns include fail protection, electrical grounding, struck-by protection, and excavation safety. The greatest number of serious injuries are due to falls, either from the roof or the side of the structure during construction. Philip C. Sunstrom, "Become the Company's OSHA Oracle", American Society for Industrial Security, Vol. 38, No. 3, pg 24 et seq.
Various scaffolding and safety systems have been proposed. Some are engineered from the ground up while others are deployed so as to hang off the roof or wall structure. All of these scaffold systems, however, suffer from a common defect--the enormous amount of time to assemble, erect, reposition, and take down such systems.
For the average commercial construction project, it takes approximately 4.5 man days (i.e., three workers for a day and a half) to set up a two-story, 100 foot long scaffold system and approximately three man days take it down. This results in a double cost; one related to the actual labor costs associated with the scaffold assembly/disassembly process, and the other a productivity loss since work on the main project is delayed by the time necessary to erect the scaffold. This double cost leads to partial or non-compliance with OSHA regulations, jeopardizing worker safety.
Hanging scaffolds, that is, scaffold systems that are affixed to the roof and hang over the cave to support a working platform, have been proposed to reduce the amount of labor and time necessary for scaffold assembly/disassembly. While saving some time, these hanging scaffolds are not without their own shortcomings.
For example, the roof anchoring point of the hanging scaffold system is critical as it must withstand thousands of pounds of force in several directions while the construction work is in progress. Typically, the roof anchor is thus nailed, bolted or fixedly attached in some other way to the roof to provide the necessary safety margin. However, this results in a roof anchoring system that requires additional time and effort to remove and reposition, thereby reducing the time savings associated with the hanging scaffold system.
Furthermore, many hanging scaffold systems are theoretically designed for easy pre-assembly prior to deployment, again with the objective of reducing labor costs and cutting productivity losses. Most of these hanging scaffold systems, however, are not as stable as ground based scaffold systems.
Accordingly, a need exists for a versatile, stable and safe roof anchoring and hanging scaffold system that is easy to erect, reposition and take down.